Dryer with antiwrinkle cycle



Aug. 27, 1968 F. c. HARTER 3,398,462

DRYER WITH ANTIWRINKLE CYCLE Filed Oct. 18, 1966 BY -14; 94 4M. am a, ATTORNEYS United States Patent 3,398,462 DRYER WITH ANTIWRINKLE CYQLE Franklin C. Harter, Stevensville, Mich, assignor to Whirl pool Corporation, Benton Harbor, Mich., a corporation of Delaware Filed Oct. 18, 1966, Ser. No. 587,552 7 Claims. (Cl. 34-45) ABSTRACT OF THE DISCLOSURE A clothes dryer having a control system to provide a plurality of different, selectively available, drying cycles each of which includes a terminal antiwrinkle period of intermittent rotation of the dryer drum to eliminate wrinkles in dried clothes. The control system automatically provides a different period of intermittent drum rotation in one special drying cycle to protect certain types of fabrics.

The present invention relates to a dryer for clothes and the like incorporating an improved type of antiwrinkle cycle.

In preceding applications, assigned to the same assignee as this application, there have been described various types of dryer apparatus which incorporate an antiwrinkle cycle. Basically, this cycle consists in tumbling the clothes at the conclusion of the regular dryer interval (and at the conclusion of any cool-down period following the application of heat) for short periods of time at regular intervals. 9

Typically, the dryer drum may be rotated for a period of about ten seconds every five minutes. This interval is sufficient to rearrange the clothes in the dryer and has been found effective to inhibit the formation of deep-set wrinkles in the clothes. Generally, the antiwrinkle cycle continues until the operator opens the door, whereupon the entire circuit is disabled, or a predetermined amount of running time has expired in the timer means which programs the dryer through its various cycles.

In a typical dryer assembly incorporating an antiwrinkle cycle, the operator has the option of selecting drying cycles of varying intensities, to take into account the different drying characteristics and sensitivity to heat of the various types of fabrics which are being dried. With the types of systems previously proposed it was common practime to employ a timer which had a predetermined time interval of operation left, usually on the order of fifteen minutes, after the actual drying phase of the dryer operation had concluded. Typically, this fifteen minute interval was then divided between a five minute cool-down period and a ten minute interval of operation during the antiwrinkle cycle. With an antiwrinkle interval of ten seconds duration every five minutes, this meant that the timer would actually remain in the circuit for an additional five hours after the cool-down period.

This type of circuitry was satisfactory for normal types of fabrics, but was not the best for the new wash n wear fabrics which, more desirably, should be provided with a ten minute cool-down period, and the remaining five minutes would be allocated to the antiwrinkle cycle, thereby reducing the total duration to about two and onehalf hours.

The present invention provides a control system for a dryer which makes it possible to allocate timer running time between a cool-down period and an antiwrinkle cycle without changing the total duration of the time the timer is energized. Consequently, the system of the present invention is particularly useful for dryers which are equipped to handle wash n wear fabrics, since it is possible with the system of the present invention to automatically provide optimum cool-down and antiwrinkle durations for such fabrics.

3,398,452 Patented Aug. 27, 1968 One of the objects of the present invention is to provide an improved dryer assembly including a control circuit which makes it possible to selectively choose a cool-down cycle and an antiwrinkle cycle most suitable for the particular type of fabric being dried.

Another object of the invention is to provide a circuit for allocating timer running time between the cool-down period and an antiwrinkle cycle whereby the operator by manipulation of a single control can choose the cool-down and antiwrinkle durations which are best suited for the fabrics involved.

Other objects and features of the present invention will become apparent to those skilled in the art from the following description of the accompanying drawings which illustrate a preferred embodiment.

FIGURE 1 is an electrical schematic diagram of a control system embodying the invention;

FIGURE 2 is a chart showing the disposition of the various switches when certain programs are selected;

FIGURE 3 is a chart showing the disposition of timer operated switches at various stages in the cycle; and

FIGURE 4 is a fragmentary enlarged view illustrating a pulser motor contact switch arrangement.

As shown in the drawings:

In the embodiment illustrated in the drawings, reference is made to an electrically heated dryer although it should be recognized that the control circuit of the present invention is equally applicable in the control of gas-fired dryers. Also, the illustrated embodiment makes use of an automatic sensing system for terminating the introduction of heated air into the drum, the system being based, for example, upon sensing means located in the air being vented from the dryer which terminates the operation of the heater when the exit air reaches a predetermined temperature. Obviously, this system is also applicable to dryers which involve introduction of heated air for a predetermined time interval, or to dryers which use the new electronic sensing means which uses the electrical conductivity of the clothes themselves as a means for gauging the extent of drying.

In FIGURE 1, reference numerals 10 and 11 have been applied to two terminals of an energizing line which, for example, feed a -volt alternating current to the system. A third terminal 12 is provided to supply a 240-volt alternating current to the heater system of the dryer assembly.

As illustrated in FIGURE 2, the control system of the drawing includes five manually operable selector switches which are located on the console (not shown) and provide the operator with the selection of a heavy duty cycle, a regular cycle, a wash n 'wear cycle, a delicate fabric cycle, and an air only cycle. The following description assumes that the pushbutton for the heavy cycle has been pressed thereby closing a switch 13 and introducing a relatively high temperature thermostat 14 into the heater control circuit. The door of the dryer is closed, closing a door-operated switch 16. When the selection for the particular drying cycle has been made, the start switch 17 is closed, thereby initiating operation of the dryer.

As seen in FIGURES 1 and 3, a timer motor 18 controls the closing of five switches 19, 21, 22, 23 and 24. At the outset of the drying period, only switches 19, 21, 22 and 24 are closed by the cams 20 driven off the shaft of the timer motor 18.

The commencement of the dryer cycle also energizes a relay coil 26 which controls the operation of switches 27, 28 and 29 as illustrated in FIGURE 1. The closing of the timer operated switch 21 provides energization for the relay coil 26 through the selector switch 13, thermostat 14, the coil 26, the start switch 17 and door switch 16. The closing of the relay control switch 29 provides a holding contact for the relay coil 26 so that the switch 17 1 may be released after the relay has operated.

The heater circuit is also energized at this time, since the timer operated switch 19 is closed, and the relay operated switch 27 is also closed. The energizing circuit in cludes an overload thermostat 31, an electrical heater element 32, and a centrifugal switch 33 which closes when the dryer motor reaches its normal running speed.

A drive motor 34 is also energized at this time, since the timer operated switches 21 and 22 are closed. The motor 34 includes a start Winding 36 and a running winding 37. Initially, both windings are energized since a centrifugal switch arm 38 engages a terminal 39 and places the two windings in parallel. Upon reaching operating speed, however, the centrifugal switch '38 moves to a contact 41 where only the running winding 37 remains in the circuit.

While four of the five timer operated switches are closed at the initiation of the drying cycle, the timer motor 18 itself is not yet energized.

During the drying cycle, the clothes in the drum are tumbled and heated. After the clothes load reaches a predetermined temperature, the thermostat 14 opens periodically. This deenergizes the relay coil 26 so that the heater 32 is deenergized due to the opening of the switch 27. When the relay 26 is deenergized, the normally closed contact switch 28 closes, so that the timer motor 18 is energized when the heater 32 is off. This periodic opening and closing fo the thermostat 14 and periodic energization of the relay coil 26 continues until the lapse of a certain amount of predetermined timer motor running time. When this occurs, the switch 23 closes and the timing arrangement is such that this switch closes about one minute or so before the switch 19 opens. The switch 23 remains closed and as switch 19 opens, the heater 32 is completely removed from the circuit and the predetermined cool-down interval then begins.

During the cool-down interval, the motor 34 continues to run because switches 21 and 22 remain closed. Since the heater 32 is now off, after a few minutes time the thermostat 14 will close because the temperature of the load has dropped. This energizes the relay 26 which remains energized for the remainder of the cool-down portion. The timer still remains energized since the switch 23 is closed. Eventually, the timer will accumulate enough running time to open the switch 22. This ends the cooldown cycle and begins the antiwrinkle cycle.

The opening of the switch 22 causes the motor 34 to stop running. However, the relay 26 is still energized through switch 21, switch 13, the high temperature thermostat 14, switch 29 and door switch 16. Thus, the relay controlled switch 29 is closed and the relay controlled switch 28 is open. The timer 18 is energized through switch 21 and a pulser system which includes a movable contact 43 which is arranged to sequentially close a pair of contacts 44 and 46. With the contact 43 closing the contacts 44, the ciruit to the timer motor '18 is completed through the switch 21, contacts 43 and 44 and timer control switch 23. This also energizes the drive motor 34 so that the timer motor 18 and the drive motor 34 each run concurrently at intervals of approximately ten seconds each five minutes.

The antiwrinkle interval is determined by a pulser motor contact system which may be of the type illustrated in FIGURE 4 of the drawings. The movable contact arm 43 may take the form of a resilient spring arm which has a depending feeler portion 47 arranged to ride on the surface of a cam 48. As the cam 48 is rotated in the clockwise direction as viewed in FIGURE 4, the feeler 47 eventually drops into a notch 49, thereby closing switch contacts 46 while leaving switch contacts 44 still open. After a short interval, the feeler arm 47 drops into a lower notch 51 whereupon switch contacts 44 close. When the feeler 47 is lifted out of the notch 51, it rides on the surface of the cam 48 and both switch contacts again reopen. Thus, the dwell time of the 'feeler 47 in the notches can be adjusted to provide the required antiwrinkle interval. On the assumed basis of ten minutes running time remaining in the timer motor 18, and an antiwrinkle interval of ten seconds every five minutes, the antiwrinkle cycle will continue for a total of five hours. Finally, the timer control switch 21 opens, ending the antiwrinkle cycle and terminating the operation of the dryer. Any time before the cycle is terminated, the operator can terminate the dryer operation by opening the access door, thus opening the switch 16. This deenergizes the pulser motor 45 and the relay coil 26 so that the dryer operation is completely terminated. If the door should be reclosed, the antiwrinkle cycle does not resume since once the relay contact 29 is open, the relay 26 can no longer be energized. Also, when the door is reclosed, a switch 53 coupled to the switch 16 opens so that the indicator lamp 54 is no longer connected to the line thereby indicating to the operator that the cycle is over.

The foregoing description has dealt with the operation of the system of the heavy cycle but it should be recognized that the same operation exists in the regular and delicate cycles. To this end, the manually operable selector switch 56 and a medium range thermostat 57 are included in the circuit in parallel with the selector switch 13 and the high temperature thermostat 14 to control operation of the circuit for a regular drying cycle. Similarly, the manually operable selector switch 58, and a low temperature thermostat 59 are included to control operation of the circuit during the delicate cycle.

When the air only selector button is pushed, the clothes are tumbled without any heat for a predetermined time period. Closing the air only selector button closes a switch 61 in series with the switch 24, and since switch 24 is closed along with the timer operated switch 21, the drive motor 34 and the timer motor 18 are energized for the period during which the switch 24 is closed.

When the wash n wear cycle is selected, switches 56 and 61 are both closed. The heating of the clothes during the heating cycle is substantially the same as that described previously, except that the medium temperature thermostat 57 is in the circuit during clothes drying. The wash n wear cycle employs a conditioning means which extends the cool-down cycle.

At the conclusion of the five minute cool-down period provided by the circuit as described previously, when the switch 22 opens the switch 24 has been closed and stays closed for an additional five minutes so that it takes over the function of the switch 22. Consequently, the drive motor 34 and the timer motor 18 are energized through the switch 21, the serially connected switches 61 and 24 and the timer operated switch 23. The drive motor 34 and the timer 18 continue to run for an additional five minute cool-down period and, at the end of this extra cool-down period, the timer operated switch 24 opens and the machine goes into the regular antiwrinkle cycle as previously described. However, since ten minutes of accumulated timer motor time has now been used up in the cool-down cycle, only five additional minutes are available for the antiwrinkle cycle. Since the pulser motor 45 drives the drive motor 34 and the timer motor 18 for ten seconds every five minutes, this reduces the total available antiwrinkle time to two and one half hours.

It is desirable to provide a signal to the operator at the beginning of each antiwrinkle cycle. For this purpose, an audible signal such as a bell 62 is provided. The bell 62 is actuated when the switch arm 43 contacts the contacts 46 prior to the tumbling interval of the antiwrinkle cycle. There is no signal at any time during the normal heating and cool-down cycles, since the switch arm 43 and the contacts 46 and 44 are then shorted out by the timer operated switch 22.

While the foregoing description was based upon the use of automatic sensing means to terminate the introduction of heated air into the drying drum, the system of the present invention is also applicable to a strictly timed cycle where the termination of the heating is accomplished by the timer itself. In this case, as illustrated in FIGURE 3 of the drawings, the switch 19 is opened by the timer at the expiration of a predetermined time interval. The switch 23, however, is closed at the beginning of the drying cycle and continues to be closed throughout the cycle so that the timer motor 18 runs as long as switches 21 and 22 are closed (and relay operated contact 29 is closed).

From the foregoing, it will be understood that the system of the present invention provides a convenient means for selecting cool-down and antiwrinkle periods of varying duration without using elaborate circuitry for each. The circuit uses only a single timer motor and a single pulser, thereby achieving the benefits of the invention without a substantial increase in cost.

It should be evident that various modifications can be made to the described embodiments without departing from the scope of the present invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A dryer apparatus having a rotatable drum and including:

a plurality of first selector means for selecting one of a plurality of drying cycles, each drying cycle comprising drying time, cool-down time, and antiwrinkle time,

pulser means for causing intermittent rotation of said drum during the antiwrinkle time,

timer means operable to provide a predetermined interval of drum rotating time for the combination of cool-down and antiwrinkle time, and

circuit means actuated by one of said plurality of selector means to operate said timer means for a cool-down time interval in excess of the cool-down time interval for the others of said cycles.

2. A dryer apparatus having a rotatable drum,

a plurality of manually operable selector switches for selecting one of a plurality of drying cycles of differing intensity,

timer means operable at the conclusion of each of said drying cycles to program said apparatus through a cool-down period followed by an antiwrinkle cycle, first switch means operated by said timer to cause rotation of said drum during said cool-down period, and

second switch means operated by one of said selector switches to energize said timer means for an additional predetermined interval and thereby prolong the cool-down period for that selected drying cycle.

3. The dryer apparatus of claim 2 which includes:

a timer operated switch in series with said second switch means, said timer operated switch being closed during each of said drying cycles whereby closing of said second switch means provides a bypass about said first switch means when said first switch means opens. 4. The dryer apparatus of claim 2 in which said timer means is arranged to provide a predetermined interval of timer operation for the combination of cool-down operation and antiwrinkle operation.

5. A fabric drying apparatus comprising:

a rotatable drum for receiving fabrics to be dried and drive means for rotating said drum,

a first control circuit for operating said drive means through a drying cycle,

a second control circuit for operating said drive means through a cool-d-own cycle, and

a third control circuit for intermittently operating said drive means urging an antiwrinkle cycle,

a plurality of manually operable selector switches, means interconnecting one of said selector switches with said second circuit to provide a first predetermined time for said cool-down cycle, and with said third circuit to provide a second predetermined time for said antiwrinkle cycle, and

means interconnecting another of said selector switches with said second circuit to provide a third predetermined time for said cool-down cycle and with said third circuit to provide a fourth predetermined time for said antiwrinkle cycle.

6. The apparatus of claim 5, wherein said third time is longer than said first time, and said fourth time is shorter than said second time.

References Cited UNITED STATES PATENTS 11/1966 Orr et a1 34-45 XR 11/1966 Morrison et al. 34-45 FREDERICK L. MATTESON, JR., Primary Examiner.

A. D. HERRMANN, Assistant Examiner. 

